An easily modified method using FeCl 3 to synthesize nanoporous gold with a high surface area

Here, we report a two-step dealloying method using ferric chloride to synthesize nanoporous gold (NPG), instead of the traditional corrosive nitric acid method. In the new method, the pore size can be easily controlled by using various solutions and additives. For example, when using ethylene glycol (EG) as a solvent, the NPG (NPG-EG) pore size can be made as small as 8 nm, thus increasing the electrochemical specific surface area of the NPG to seven times higher than that of traditional NPG with a pore size of 25 nm. NPG-EG showed an enhanced capacitance of 1340 F g −1 at a current density of 2.0 A g −1 when electrodeposited with Ni 3 S 2 .